1. Field of the Invention
The present invention relates to a jig for producing optical parts. In particular, the present invention relates to a jig for producing parts, which is preferably used, for example, to polish each of end surfaces of array members secured to optical coupling ends of optical fibers led from reels around which the fibers are wound in a predetermined number of turns respectively.
2. Description of the Related Art
Recently, an optical fiber gyroscope has been suggested, which is extremely advantageous in operability, convenient handling performance, and realization of a compact and light weight system, and which is also advantageous in improvement in durability because there is no mechanically movable component. Development is being rapidly advanced at present in order to practically use such an optical fiber gyroscope.
The system of the optical fiber gyroscope will now be briefly explained. The optical fiber gyroscope is a sensor for detecting the angular velocity based on the phase difference (Sagnac phase difference) between two light beams transmitted clockwise and counter clockwise in a fiber coil obtained by winding an optical fiber having a length of several tens meters in a predetermined number of turns. The optical fiber gyroscope is classified into those belonging to the open loop system and those belonging to the closed loop system depending on the method for detecting the phase difference.
When it is intended to produce an optical part such as an optical fiber gyroscope which is excellent in, for example, compact and light weight properties and durability as described above, the process for assembling the optical part especially comprises the steps of winding a lengthy optical fiber around a cylindrical object to produce a fiber coil, optically coupling an optical IC chip (optical waveguide)incorporated with a phase modulator to two ends of the optical fiber led from the fiber coil, optically coupling an optical fiber led from a light source to an optical fiber to be led to a photodetector by using a coupler, optically coupling an optical fiber led from the coupler to the optical IC chip, and packaging the optical IC chip.
In the step of optically coupling the optical IC chip to the optical fiber as described above, the following procedure is assumed. That is, an array member is secured to an optical coupling end of the optical fiber to make optical coupling to the optical IC chip. Thus, for example, a start end and a terminal end of the optical fiber are optically coupled to the optical IC chip.
According to such a procedure, the use of the array member makes it possible to previously define the spacing distance between the both ends in conformity with the coupling portion of the optical IC chip. Further, the direction of the polarization plane of the light transmitted through the optical fiber can be adjusted beforehand to the direction of the polarization plane of the light transmitted through the optical waveguide. Therefore, when the optical fiber is actually optically coupled to the optical IC chip, it is unnecessary to consider the spacing distance and the direction of the polarization plane one by one. Accordingly, it is possible to contemplate an efficient operation of the optical coupling.
Before the array member, which is secured to the end of the optical fiber led from the reel, is attached to the optical IC chip, the surface of the array member, on which the array member is attached to the optical IC chip, is previously polished. By doing so, it is possible to make highly accurate optical coupling between the optical fiber and the optical IC chip.
In order to polish the array member, the following method is assumed. That is, for example, a reel-placing stand is installed outside a rotary polishing surface plate. A reel is placed on the reel-placing stand, and the optical fiber is drawn from the reel so that the array member secured to is end is positioned on the polishing surface plate. Further, the array member is polished while allowing the end surface of the array member to contact with the polishing surface plate. In this method, the array member is pressed against the polishing surface plate manually or by using a mechanical chucking mechanism.
When the performance for mass production is taken into consideration, the following method is assumed. That is, for example, ten individuals of reel-placing stands are installed around the polishing surface plate. Reels are placed on the respective reel-placing stands. The array members, which are secured to ends of optical fibers drawn from the respective reels, are positioned on the polishing surface plate to polish the ten array members in the same manner as described above.
However, in the case of the polishing methods as described above, a skilful technique is required to correctly position, on the polishing surface plate, the end surface of the array member secured to the end of the optical fiber drawn from the reel. Further, it is impossible to perform the polishing operation while allowing the array member itself to make rotation on its axis. Therefore, a problem newly arises in that the dispersion in polishing accuracy tends to increase among the array members.